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It's been a long-standing belief in some circles that using the multitasking feature of iOS to force quit apps can help save an iPhone's battery life, or improve the speediness of the software when the smartphone becomes slow. Earlier in the week, an iPhone user decided to email Apple CEO Tim Cook to put the issue to bed once and for all, and instead got a reply from Craig Federighi, Apple's senior VP of Software Engineering (via 9to5Mac).

Asked specifically whether Cook quits apps to save battery and if it's truly "necessary for battery life," Federighi jumped in with a concise "no and no." Although far from an official condemnation of the force quit belief by Apple, it is the most the company has directly said about the myth in the six years since multitasking became available in iOS 4.

multitasking-battery-email.jpg
Image via 9to5Mac


The simplistic nature of swiping apps off of the multitasking landing pad, and subsequently "quitting" them, helped create a widespread belief that an iPhone's battery could be preserved for a little longer. But as many have pointed out over the years, doing so could in fact do the complete opposite: you could be shortening the battery life of your iPhone.

A few exceptions can be made to certain processes, but for the most part when an app is pushed into the background it becomes completely frozen and ceases to use any of an iPhone's battery power. As relayed by a former Genius Bar technician, Scotty Loveless, force quitting an app purges all of its code from the RAM of the iPhone, requiring it to be re-loaded upon the next time you visit the app.

If it's an app you're going to often -- a weather or traffic experience, for example -- all of the forced closing and re-opening actually can worsen the life of an iPhone. Exceptions can be made by toggling off a feature called "Background App Refresh," which the Facebook app was found to be suspiciously circumventing in recent months, but in all other occurrences the process of force quitting each app to prolong battery life is erroneous.
Plus, iOS closes apps automatically as it needs more memory, so you're doing something your device is already doing for you. You are meant to be the user of your device, not the janitor. The truth is, those apps in your multitasking menu are not running in the background at all: iOS freezes them where you last left the app so that it's ready to go if you go back.

Unless you have enabled Background App Refresh, your apps are not allowed to run in the background unless they are playing music, using location services, recording audio, or the sneakiest of them all: checking for incoming VOIP calls , like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon to alert you it is running in the background.
In the case of the Facebook app, the company's mobile app was discovered to be the cause behind cases of dramatic battery drain, even when Background App Refresh was turned completely off. The social network site eventually implemented a fix for the problem, citing the major culprits as "CPU spin" in the app's code and silent background audio continuing to emanate from the service's auto-play videos after the app was closed.

That was a rare case, however, and users should stick closer to Federighi's succinct advice today instead of continuing to put long-term strain on the smartphone. If you're ever really concerned about daily battery usage, Apple offers a simple but useful tool to keep on top of things. Go to Settings > Battery > and scroll down to Battery Usage. "Last 24 Hours" and "Last 7 Days" can give you a full picture at where the heaviest-hitting battery life apps are coming from.

You can also restrict specific app access to Background App Refresh -- or turn it off altogether, although that can drastically hinder certain apps' key features -- in Settings > General > Background App Refresh.

Article Link: Apple Reiterates: Force Quitting iOS Apps Doesn't Help Battery Life
 
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GQB

macrumors 65816
Sep 26, 2007
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"or the sneakiest of them all: checking for incoming VOIP calls , like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon "

Why the exception for Skype?
 
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xero9

macrumors 6502a
Nov 7, 2006
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If this is true, then why is everyone complaining about Facebook draining their battery while mine seems to be unaffected?

I think 9/10 times it won't have any effect, but to say it does nothing I think is untrue.
 
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xero9

macrumors 6502a
Nov 7, 2006
860
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"or the sneakiest of them all: checking for incoming VOIP calls , like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon "

Why the exception for Skype?

What is this icon you speak of? I've tried with Fongo and Bria and neither put any indication on the bar at the top.
 
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Tannerjr

macrumors newbie
Apr 28, 2008
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Maybe Federighi ought to let his genius bar peeps in on this. every. SINGLE. time I've asked about battery life in the apple store, the genius bar apt. nets me the usual battery graph showing that mine is fine and they recommend closing apps I'm not using...
 
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jmcrutch

macrumors regular
Jul 27, 2010
249
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Maybe Federighi ought to let his genius bar peeps in on this. every. SINGLE. time I've asked about battery life in the apple store, the genius bar apt. nets me the usual battery graph showing that mine is fine and they recommend closing apps I'm not using...

Same thing here - i've argued with Apple Store employees about this before.
 
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chriscrowlee

macrumors 65816
Aug 10, 2015
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The questions asked was "Is it necessary?" and "Do you do it?" and both answers were no.

The question should have been "Is it beneficial in any way?" which the answer would be yes.

Not sure why the site is picking this up as evidence there's no benefit, because neither reply indicates that. However small, there most certainly is benefit. Killing an app ends the process that second. By leaving it open, there is a fraction of a second where it continues to use the processor, and some apps are known to sneak in the background (ie Facebook).
 
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'Dorian

macrumors member
Aug 30, 2014
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Where it's warm
It never seemed to give me any extra battery life. I still do it when it fills up with 30 or 40 apps and wish there were just a close all button. With Craig answering however, I don't think there is anyone more qualified to give a statement on it. Sometimes I think their short answers are just them being smug, but then I realize they probably do it because it's harder to misinterpret.

Now everyone stop bugging them so they can concentrate on designing my mac mini quad core with hdmi 2.0!
 
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Mascots

macrumors 68000
Sep 5, 2009
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"or the sneakiest of them all: checking for incoming VOIP calls , like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon "

Why the exception for Skype?

I'm not too familiar with how VoIP backgrounding works, but I believe the actual process of checking for incoming calls is handed off to iOS which then suspends your app and reawakens it when data is pushed through the channel it is expected. I think...

Edit: Yep:
Rather than keep VoIP apps awake all the time, the system allows them to be suspended and provides facilities for monitoring their sockets for them. When incoming traffic is detected, the system wakes up the VoIP app and returns control of its sockets to it.
 
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